JPH07306444A - Camera - Google Patents

Abstract

PURPOSE:To reduce camera-shaking and simultaneously to obtain a shutter speed of a 1/8000 second or more by providing a shutter mechanism including a spatial optical modulation element (DMD: digital micromirror device) arranged on the focal plane of an optical system photographic lens. CONSTITUTION:The DMD 102 and a driving circuit 103 are provided instead of a shutter and a mirror, the position of a silver salt film 106 is changed and a film side lens 107 is added to the full surface of the film 106. Then, a finder is moved to a side opposite to the silver salt film 106 acrossing a photographic lens 101 and a finder side lens 108 is arranged on the full surface of the finder. The driving circuit 103 drives the DMD 102 so as to change the angle of reflection of the DMD 102 from an optical path 104 to an optical path 105, when a shutter button is depressed. The DMD 102 is controlled by the driving circuit 103 to change the angle of reflection of light made incident on the DMD 102 from the optical path 104 to the optical path 105 or from the optical path 105 to the optical path 104 at 10 microseconds.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a spatial light modulator (Digital Microwave) for a shutter mechanism and a mirror mechanism.
The present invention relates to a camera using an error device.

[0002]

2. Description of the Related Art A conventional camera having a shutter mechanism and a mirror mechanism has a structure as shown in FIG. In FIG. 1, the subject light emitted from the subject is condensed by the photographing lens 1 adjusted so that the subject light is focused on the silver salt film 6, and is adjusted to a predetermined light amount by the diaphragm 2. To reach. When the shutter button is not pressed, the subject light that has reached the mirror 3 is reflected by the mirror 3 at the position shown in the figure, advances to the optical path 10, and is reflected inside the pentaprism 4 to reach the finder.
When the shutter button is pressed, the mirror 3 bounces up and the subject light that has passed through the diaphragm 2 travels to the optical path 11 and reaches the shutter 5. The shutter 5 moves in front of the silver salt film 6 immediately after the mirror 3 jumps up. The shutter speed is controlled by the preset interval of the slit 7. The subject light that has reached the shutter 5 passes through the moving slit 7 and reaches the silver salt film 6 to expose the silver salt film 6 to light. When the shutter 5 has finished passing in front of the silver salt film 6, the interval between the slits 7 is set to 0 and the shutter 5 returns to its original position and at the same time the mirror 3 also returns to its original position.

[0003]

In the conventional technique as described above, since the movable parts of the shutter and the mirror have a large mass, the vibration generated when the shutter and the mirror move causes the camera shake. There was a problem such as becoming. Also, because of such a configuration, as for the increase of the shutter speed, it is currently 1 /
There was also a problem that the maximum speed was 8000 seconds.

The present invention has been made in view of the above-mentioned conventional problems, and a mechanism having a small mass is provided in place of these movable parts to reduce camera shake.
It is an object to provide a camera that realizes a shutter speed of / 8000 seconds or more.

[0005]

To achieve the above object, in the present invention, in a camera having an optical system for forming an optical image of a subject on a film and a shutter mechanism, a focal plane of a taking lens of the optical system is provided. The first means for solving the problem is to have a shutter mechanism including the spatial light modulator arranged above. Also, the spatial light modulator is a Digital Micromirror Device.
(Hereinafter referred to as DMD) is a means for solving the second problem, the shutter mechanism has means for changing the reflection angle of the spatial light modulation element, and has an angle for guiding the optical image to the film surface at the time of photographing. Setting is the third means for solving the problem, and the means for changing the reflection angle is to set the reflection angle of the spatial light modulation element to an angle that guides the optical image to the finder except during photographing. As a means for solving the above-mentioned problem, a light-shielding member provided with a movable light-shielding portion arranged at a light entrance portion to the film and a light-shielding member driving means for driving the movable light-shielding portion are provided. age,
The means for activating the light-shielding member driving means is a shutter button or a separately provided switch, which is a means for solving the sixth problem.

[0006]

In the present invention, a DMD having almost no mass of moving parts is used in place of the conventional shutter mechanism and mirror mechanism, so that hand shake can be reduced and a shutter speed of 1/8000 seconds or more can be realized. it can.
A brief description of the DMD will be added here.

The DMD uses a movable mirror array chip and has high light utilization efficiency. Each mirror on the chip corresponds to a pixel, and each of them rotates up to 20 degrees about a diagonal line of the square. By shining light on this, the reflection angle of light can be changed by up to 20 degrees for each pixel.
Bright (on) by using only the light reflected in a specific direction
Create a state and a dark (off) state. The time (response speed) required for the mirror to change from the ON state to the OFF state is as fast as 10 microseconds.

[0008]

The present invention will be described below with reference to the drawings. Figure 2
Is an embodiment of the present invention, in which a DMD 102 and a drive circuit 103 are provided instead of the shutter 5 and the mirror 3, the silver salt film 6 moves to the position of the silver salt film 106, and the film side lens is provided on the entire surface thereof. 107 is added, and the viewfinder sandwiches the taking lens 101 and the silver salt film 1
The lens 108 is moved to the side opposite to 06, and the finder side lens 108 is arranged on the entire surface thereof. The drive circuit 103 is a circuit that drives the DMD 102 so as to change the reflection angle of the DMD 102 from the optical path 104 to the optical path 105 when the shutter button is pressed. The DMD 102 is controlled by the drive circuit 103, and the reflection angle of the light incident on it is
It is an element that changes from the optical path 104 to the optical path 105 or vice versa in 10 microseconds. Film side lens 107
Is a lens for forming a subject image on the DMD 102 on the silver salt film 106. The finder-side lens 108 is a lens that guides the optical image on the DMD 102 to the finder. The taking lens 101 is a lens that forms an image of a subject on the DMD 102. The other functions are the same as those of the conventional camera.

The subject light emitted from the subject is condensed by the photographing lens 101, adjusted to a predetermined light amount by the diaphragm 2, and imaged on the DMD 102. When the shutter button is not pressed, the drive circuit 103 is DM
D so that the subject image on D102 is reflected to the optical path 104
The reflection angle of the MD 102 is set. The subject image reflected on the optical path 104 by the DMD 102 is condensed by the finder side lens 108 and reaches the finder.

The silver salt film 106 is loaded in the light shielding member 109, and a light shielding movable portion 109a is provided on the light path 105 side of the light shielding member 109. Shading movable part 109
A is driven by the light shielding member driving means 110 at the time of photographing. In addition, it is always maintained in the closed state during non-shooting.
The light-shielding movable portion 109a is for preventing exposure (low-intensity long-time exposure) due to stray light or the like, does not need to be operated at high speed, and does not require high accuracy.

The operation of the embodiment of the present invention will be described below. When the shutter button is pressed halfway, the light blocking member driving means 110 is activated, and the light blocking movable portion 109a of the light blocking member 109 is opened thereby. Then fully press the shutter button. When the shutter button is pressed all the way down,
In the drive circuit 103, the subject image on the DMD 102 is transmitted through the optical path
The DMD 102 is driven so as to be reflected at 5. DMD1
02 is driven by the drive circuit 103 so as to change the reflection angle, the reflection angle is changed to the optical path 10 in 10 microseconds.
4 to the optical path 105. The subject image reflected on the optical path 105 by the DMD 102 is the film-side lens 10
An image is formed on the silver salt film 106 via 7 and is exposed.

When the drive circuit 103 finishes changing the reflection angle of the DMD 102 for a preset time, the drive circuit 103 returns to DM again.
D so that the subject image on D102 is reflected to the optical path 104
Drive the MD 102. The DMD 102 is a drive circuit 103
Is driven to return the reflection angle to the original state, the reflection angle is returned from the optical path 105 to the optical path 104 in 10 microseconds. When the optical path returns to 104, the light shielding member driving means 110 closes the light shielding movable portion 109a. In this way, the exposure of the silver salt film 106 is completed.

In the embodiment of the present invention, the light-shielding portion is opened and closed by interlocking with the shutter button, but this opening and closing may be provided with a special start switch outside the camera. Although the present invention has been described with reference to the application example of the single-lens reflex camera, it is needless to say that the present invention can be applied to a lens shutter camera without being limited to this.

[0014]

As described above, according to the present invention, since the optical path can be changed by the DMD in 10 microseconds, a shutter speed of 1 / 100,000 seconds, which corresponds to the exposure time of 10 microseconds, can be realized, and Not only does the shutter mechanism and the mirror mechanism which have a large mass of the movable portion become unnecessary, but the mass of the movable portion of the DMD is extremely small, so that vibration does not occur when the optical path is changed, and hand shake is extremely small. It plays.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram illustrating a conventional camera.

FIG. 2 is a schematic configuration diagram illustrating an embodiment of a camera according to the present invention.

[Explanation of symbols]

 1, 101 Projection lens 2 Aperture 3 Mirror 4 Penta prism 5 Shutter 6,106 Silver salt film 7 Slits 10, 11, 104, 105 Optical path 102 DMD 103 Drive circuit 107 Film side lens 108 Finder side lens 109 Light blocking member 109a Light shielding movable part 110 Light-shielding member driving means

Claims (6)

[Claims] 1. A camera having an optical system for forming an optical image of an object on a film and a shutter mechanism, the shutter mechanism including a spatial light modulator arranged on a focal plane of a taking lens of the optical system. A camera characterized by having. 2. The camera according to claim 1, wherein the spatial light modulator is a DMD. 3. The camera according to claim 1, wherein the shutter mechanism has means for changing a reflection angle of the spatial light modulator, and is set to an angle for guiding the optical image to a film surface at the time of photographing. 4. The camera according to claim 3, wherein the means for changing the reflection angle sets the reflection angle of the spatial light modulator to an angle that guides the optical image to the finder except when photographing. . 5. A camera according to claim 3, further comprising a light-shielding member having a movable light-shielding portion arranged at a light-incident portion of the film, and a light-shielding member driving means for driving the movable light-shielding portion. . 6. The camera according to claim 3, wherein the means for activating the light-shielding member driving means is a shutter button or a switch provided separately.